In 28 years and 50,000+ nm of cruising from Puget Sound to Glacier Bay, and well over 1000 nights at anchor, we have never had to anchor in more than 70 feet. The vast majority of the time between 25 and 55 feet. Whether in our 26-footer, with 40 feet of chain and 300 rope, or our 37 footer, with 250 chain and 150 rope, we most often put out a scope of 3.5 or 4 to 1. If stronger winds are forecast, we might put out 5 or 6 to 1.
We anchor in a cove, positioned such that the expected wind is not coming at us across a long stretch of water. We have almost never had to use a shore tie. We carry a spare anchor, but have never lost one.
Much depends on understanding the forecast, choosing the right spot, knowing where you are on the tide, and on technique.
The Exploring series cruising guides by Don Douglass are invaluable in getting to know the anchorages, and where to drop the hook in them.
It's not that tough. Work through it a number of times, and you'll be getting comfortable. Here's a writeup on anchoring from my little book on cruising the Inside Passage in a small boat:
Anchoring
In the cruising guides you’ll find detailed descriptions of a great many anchorages along the way. Rather than discuss the anchorages themselves, we’ll discuss anchoring issues and technique (much of which you may already know), with emphasis on the nature of the Inside Passage. If you’re experienced at anchoring, there’s not much magic to it, but recognize that you will need to take into account really big tides, deep water, and potentially tough weather conditions. If you’re less experienced, anchoring safely is not that tough to learn – and it’s an essential skill for the Inside Passage.
Tidal range varies greatly from place to place, and from one time of the lunar month to another. When the sun and moon are aligned, or directly opposite each other (new moon and full moon), their gravitational effects add together, making “spring” tides which are especially large. When the moon is at 1/2, the “neap” tides are smaller. Inside Passage tides can be as small as 6-8 feet, or as large as 20 and more. You could find yourself high and dry if you don’t know where the tide is when you anchor, and how much higher, and lower it will get over the whole time you’re there. Modern chartplotters with tide tables make this easy to figure out – but make sure you get it right.
We usually anchor in 25-55 feet, and put out 90-180 feet of rode. We start by listening to the weather forecast, so we know how much wind to expect, and from what direction. Then we figure the tides, and thus the minimum depth we need. If we aren’t already quite familiar with the anchorage, we make a circle 200-400 feet across, checking depths in the area where we’ll be swinging on the hook. We do this slowly and carefully, to avoid suddenly coming across a very shallow spot – particularly where detailed charting is not available. We did wreck our props on one dark day, circling too casually in 25 feet of water, and running into a pinnacle we didn’t see, only 2 feet below the surface.
If depths look OK within the circle, and we set the anchor solidly in the center of it, we’re fairly sure we won’t wind up aground. A good way to ensure we have covered the right area, and we’re anchoring in the center of it, is to zoom way in on our chartplotter. It shows the scale of the view it’s presenting, so by looking at our track we can see quite accurately the size and shape of the area we’ve checked out.
We point into the wind, come to a stop, lower the anchor, and after the anchor and some chain is on the bottom we back slowly. After letting out the appropriate length of rode, we shift into neutral, cleat off the line, and let the boat put some tension on it. When the anchor seems to have set, we pull gently in reverse, while feeling the line for signs of dragging. Usually it’s easy to tell whether the anchor is well set or dragging. More often than not, it sets solidly right away. If it drags, we retrieve and re-set. The more wind we expect, the longer our rode, and the harder we pull to test the set.
If the wind is strong, and we’re not sure of the holding quality of this particular bottom, we leave the chartplotter on and zoomed in. If it’s really windy, we might leave both chartplotter and fishfinder on for quite a while. As we swing on the hook, our track on the chartplotter shows as a crescent, centered on the location of the anchor. If our position moves beyond the crescent, we know we have been dragging. Occasionally this happens soon after we anchor, usually because thick kelp or soft mud has prevented good holding. Then we retrieve the anchor and re-set, successfully in most cases without moving very far.
Ideally we choose a relatively small cove with protection from several angles. If we know where the wind is coming from, an anchorage that’s open for some distance in a different direction may be just fine. But suppose our anchor spot is open to the west for a mile or two, and west wind is forecast – we’re going to feel it when even a moderate west wind blows. On the other hand, if we anchor where there’s only a few hundred feet of water surface (fetch) for the wind to work on, and even more so if higher ground blocks the wind somewhat, we can ride out a pretty stiff breeze without bouncing around much. This is not just a comfort issue, but also one of safety: if waves have us pitching heavily, on the upward bounce there’s much greater strain on the rode. It could jerk the anchor out of its set and allow us to drag.
And here are some additional thoughts on anchoring our 37-footer, almost always using all chain with a 20-foot nylon bridle:
I was reading my anchoring stuff again (written 12 years ago) and realized it assumed a small boat (the sort of boat the book was aimed at) with some chain (25-50 feet) spliced to a much longer (200-300 feet) rope. For an all chain boat, I would add a writeup on the bridle, and change my description of the technique. So here's some more:
BEFORE you position the boat exactly where you want to drop the anchor, get the bridle ready by putting its chain grabber, or "chain plate", on the bow behind the windlass. Run the bridle's legs forward under the front of the bow rail, and on each side, outside the bow rail supports, back to the bow cleats. Cleat them on securely.
Rather than letting out ALL the chain you are going to put out and then backing away, let out somewhat more chain than it takes to put the anchor on the bottom, then while backing slowly (either by wind, current, or a bit of reverse power) let out the appropriate amount of chain. This avoids piling a lot of chain on top of the anchor, possibly causing it not to straighten out and set properly. The anchor may set by itself if the boat is still moving when you stop letting chain out.
Then hook the chain plate onto the chain (from the top side of the chain) right below the bow roller, and carefully let out enough more chain until tension is on the bridle, not the chain where it goes to the windlass. While operating the windlass's down switch with my left foot, I keep my right hand loosely on the right leg of the bridle as it goes out, using a little tension to make sure the chain plate stays on the chain. There should be a loop, a few feet of extra chain, hanging below the chain plate with no tension on it.
To test the set, use some reverse power (idle is usually enough) to pull on the anchor. This should tighten up the chain, and pull the chain plate up out of the water. The anchor should very clearly hold the boat motionless. The bridle legs will make some creaking noises as tension is taken up by the cleats.
